A method for predicting cutter wear of tunnel boring machines

Abstract

This invention belongs to the field of tunnel boring machine (TBM) construction technology, and particularly relates to a method for predicting cutter wear in TBMs. The method employs a TBM cutter wear prediction device, which includes various cutterheads and cutting blocks. Multiple cutterheads and cutting blocks are selected and combined sequentially to cut test soil samples. The wear amount δ of the cutting blocks rotating and cutting in the test soil sample is obtained using the following formula: Therefore, this method proposes a collaborative working mechanism based on minimizing the wear amount of different cutter combinations. Under simulated sandy and gravelly strata conditions, multiple cutter combinations are selected for testing. The wear amount of the cutting blocks in each cutter combination is calculated using the formula, and the overall tunneling capacity of different cutter combinations is uniformly and quantitatively evaluated. By rationally selecting cutter combinations with suitable tunneling capacity under specific strata conditions, the method can better simulate the wear amount under the collaborative cutting of multiple types of cutters in real-world conditions, thus achieving the purpose of cutter wear prediction.

Description

Technical Field

[0001] This invention belongs to the field of tunnel boring machine (TBM) construction technology, and in particular relates to a method for predicting the wear of TBM cutters. Background Technology

[0002] A tunnel boring machine (TBM), or shield tunneling machine for short, is a specialized engineering machine used for tunnel excavation. During construction, the TBM advances along the tunnel axis while excavating the soil. TBMs often encounter complex geological formations, such as soft-over-hard composite strata or sand and gravel layers. In these complex formations, the wear of the TBM cutterheads increases dramatically, necessitating frequent shutdowns for cutterhead replacements, resulting in significant delays, increased costs, and higher project risks. Therefore, effectively predicting cutter wear and rationally deploying the cutterheads to reduce wear, improve their operational health, and achieve long-distance tunneling is crucial. The study of TBM cutter wear, first proposed by the Cerchar Institute in France, utilizes cutter wear tests to assess the impact of rock abrasiveness on cutter wear, thus enabling research on TBM cutter wear.

[0003] However, most domestic and international research on shield machine cutter wear tests focuses on hard rock abrasion tests, with limited attention paid to tests and methods for composite strata and gravel strata. Furthermore, the use of materials similar to the cutter material, such as steel needles and steel balls, to simulate the cutter results in significant discrepancies with real-world conditions. For example, a commonly used testing method is the linear cutting machine employed by the Cerchar Institute, but it only simulates a limited range of scenarios, differing from the actual conditions encountered by shield machine cutters in real-world engineering projects. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the aforementioned problems in the prior art, this invention provides a method for predicting the wear of tunnel boring machine (TBM) cutters. This method involves setting up multiple cutter assemblies and calculating the wear amount of the cutter blocks in each assembly after use. This solves the technical problem that existing wear tests can only simulate a limited range of scenarios and cannot accurately and effectively predict the wear amount of TBM cutters during tunneling.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0008] This invention provides a method for predicting cutter wear in tunnel boring machines (TBMs). The method employs a TBM cutter wear prediction device, which includes various cutterheads and cutting blocks. Multiple cutterheads and cutting blocks are sequentially selected and combined to cut test soil samples. The wear amount δ due to the rotating cutting of the cutting blocks in the test soil sample is obtained using the following formula: in,

[0009] R is the diameter of the cutter head (mm);

[0010] N is the rotational speed of the cutter head (rpm);

[0011] v is the feed speed of the cutter head (mm / min);

[0012] L is the helical movement distance of the cutting tool block (mm);

[0013] k is the wear coefficient of the cutting tool block (g / mm). 2 ).

[0014] Furthermore, the helical motion distance of the cutting tool block is calculated using the following formula:

[0015] in,

[0016] X represents the propulsion distance (mm);

[0017] r is the installation radius (mm) of the cutting tool block on the cutter head;

[0018] ω is the angular velocity of the cutter head (rad / s);

[0019] v is the feed speed of the cutter head (mm / min);

[0020] The wear coefficient k of the cutting tool block is calculated using the following formula:

[0021] in,

[0022] s is the cutting area of ​​the cutting edge of the cutting tool block (mm);

[0023] μ V The abrasive wear constant (dimensionless) of the cutting tool block;

[0024] μ ρ To test the adhesive wear constant (dimensionless) of the soil sample;

[0025] Δm represents the mass loss (g) of the cutting tool block.

[0026] Furthermore, the mass loss Δm of the cutting tool block is calculated using the following formula: Δm=m1-m2; where,

[0027] m1 is the initial mass (g) of the cutting tool block;

[0028] m2 is the mass (g) of the cutting tool block after wear.

[0029] Furthermore, the following steps are included:

[0030] S1: The test soil sample is placed in the test cylinder, and the test soil sample is cemented, consolidated or compacted according to the different soil layer conditions to be simulated in the test.

[0031] S2: Weigh the cutting tool block and record its initial mass m1;

[0032] S3: The cutter head descends to the top surface of the test soil sample and begins to rotate, so that the cutter head enters the test soil sample while rotating, and the cutting blades cut the test soil sample.

[0033] S4: After the cutter head descends to the limit position inside the test soil sample, the cutter head rises to the top surface of the test soil sample, the cutting blade is removed, cleaned, dried and weighed, and the mass of the cutting blade m2 is recorded.

[0034] S5: Change the soil conditions of the test soil sample and the combination of various cutter heads and cutting blocks according to different test requirements, and repeat S1-S4.

[0035] Furthermore, the cutter head includes a central block, spokes, and an annular cutter holder. The central block is located at the center of the annular cutter holder, and the central block is connected to the annular cutter holder through spokes. The spokes extend along the radius of the annular cutter holder and are evenly arranged in a circle within the annular cutter holder. Multiple mounting holes are provided on the spokes, and the cutting blocks are detachably mounted in the mounting holes by bolts.

[0036] Furthermore, the device includes two types of cutter heads: a four-spoke cutter head with four spokes and an eight-spoke cutter head with eight spokes. On the bottom surface of each spoke, multiple first mounting holes are arranged equidistantly along its length, and these first mounting holes are located on the centerline of the spoke. On the two side walls of each spoke, multiple second mounting holes are arranged equidistantly along its length, and these second mounting holes are symmetrical about the centerline of the spoke. The device also includes two types of cutting blades: a shell cutter and a cutting blade. The shell cutter can be detachably mounted in the first mounting hole, and the cutting blade can be detachably mounted in the second mounting hole.

[0037] Furthermore, the shield machine cutter wear prediction device also includes a test bench, which includes a vertical support rod, a limiting plate, and a base. The limiting plate is located parallel to the base above it, and the vertical support rod is vertically supported between the limiting plate and the base. The upper end of the vertical support rod is connected to the edge of the lower surface of the limiting plate, and the lower end of the vertical support rod is connected to the edge of the upper surface of the base. The test cylinder is placed on the base and located between the limiting plate and the base.

[0038] Furthermore, the test bench also includes a top plate and a lifting device. The top plate is parallel to the limit plate and located above it. The lifting device is vertically supported between the top plate and the limit plate. The upper end of the lifting device is connected to the edge of the lower surface of the top plate, and the lower end of the lifting device is connected to the edge of the upper surface of the limit plate. The lifting device consists of four electric telescopic struts, which extend and retract synchronously to drive the top plate to reciprocate in the vertical direction.

[0039] Furthermore, the shield machine cutter wear prediction device also includes a drive device, which is located at the center of the lower surface of the top plate. The drive device moves synchronously with the top plate in the vertical direction. The drive device is connected to the cutterhead through a transmission shaft. The upper end of the transmission shaft is detachably connected to the drive device, and the lower end of the transmission shaft is detachably connected to the central block. The drive device drives the transmission shaft to reciprocate in the vertical direction to drive the cutterhead to move synchronously. The drive device drives the transmission shaft to drive the cutterhead to rotate inside the test cylinder.

[0040] Furthermore, the shield machine cutter wear prediction device also includes a PLC system control device. The PLC system control device is electrically connected to the drive device and the lifting device to control the start and stop of the drive device and the lifting of the lifting device. Before S3, the rotation speed ω and the propulsion speed v of the cutter head need to be set through the PLC system control device, and the real-time propulsion distance and corresponding propulsion time of the cutter head are collected at all times during the cutting process of the cutting block in the soil sample to be tested.

[0041] (III) Beneficial Effects

[0042] The beneficial effects of this invention are:

[0043] This invention provides a method for predicting cutter wear in tunnel boring machines (TBMs). It proposes a collaborative working mechanism based on minimizing wear of different cutter combinations. Under simulated sand and gravel strata conditions, various cutter combinations are selected for testing. The wear of the cutter blocks in each combination is calculated using formulas. The overall tunneling capacity of different cutter combinations is quantitatively evaluated, and the influence of cutter material properties, strata characteristics, and tunneling control parameters on cutter wear is investigated. This method ensures minimal wear while maintaining high tunneling efficiency. By rationally selecting cutter combinations with adaptability to specific strata conditions, it can effectively simulate the wear under collaborative cutting by multiple cutter types in real-world conditions, thus achieving the goal of cutter wear prediction. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the shield machine cutter wear prediction device.

[0045] Figure 2 This is a schematic diagram of the tool assembly one;

[0046] Figure 3 This is a schematic diagram of the tool assembly two.

[0047] Figure 4 This is a schematic diagram of the structure of tool assembly three;

[0048] Figure 5 This is a schematic diagram of the tool assembly four.

[0049] [Explanation of Labels in the Attached Image]

[0050] 1: Test cylinder; 11: Cylinder cover; 111: Pressure boosting hole; 112: Grouting hole;

[0051] 2: Cutter head; 21: Central block; 22: Spokes; 23: Circular cutter holder;

[0052] 3: Cutting tool block; 31: Shell cutter; 32: Cutting tool; 33: Center fishtail cutter;

[0053] 4: Test bench; 41: Vertical support rod; 42: Limiting plate; 43: Base; 44: Top plate; 45: Lifting device;

[0054] 5: Drive unit; 6: Drive shaft. Detailed Implementation

[0055] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0056] like Figure 1-5 As shown, the present invention provides a method for predicting the wear of tunnel boring machine cutters, which employs a tunnel boring machine cutter wear prediction device. The device includes a test cylinder 1, multiple cutterheads 2, multiple cutting blocks 3, a test stand 4, and a drive device 5.

[0057] like Figure 1 As shown, the test bench 4 includes a top plate 44, a vertical support rod 41, a limiting plate 42, and a base 43. The limiting plate 42 is parallel to and above the base 43, and the top plate 44 is parallel to and above the limiting plate 42. The upper end of the vertical support rod 41 is connected to the edge of the lower surface of the limiting plate 42, and the lower end is connected to the edge of the upper surface of the base 43, providing vertical support between the limiting plate 42 and the base 43. The test cylinder 1 is used to hold the soil sample to be tested and is placed on the base 43 between the limiting plate 42 and the base 43.

[0058] The cutterhead 2 includes a central circular block 21, spokes 22, and an annular cutter holder 23. The spoke-shaped cutterhead structure allows for a larger cutterhead opening ratio. During simulated tunneling and cutting, the cutterhead 2 experiences less resistance overall, resulting in lower torque on the cutterhead 2 and lower cutting power of the drive device 5. This reduces the power load on the drive device 5 and allows for a more accurate study of the wear on the cutting blades 3 under different geological conditions during tunneling and cutting.

[0059] The central circular block 21 is located at the center of the annular cutter holder 23. The spokes 22 extend along the radius of the annular cutter holder 23 and are evenly arranged in a circle within the annular cutter holder 23. The central circular block 21 and the annular cutter holder 23 are respectively connected to the spokes 22 by welding. Multiple mounting holes are provided on the bottom surface of the spokes 22. Multiple first mounting holes are arranged equidistantly along the length direction and located on the centerline of the spokes 22. Multiple second mounting holes are arranged symmetrically about the centerline of the spokes on both side walls of the spokes 22, also equidistant along the length direction. The cutting blade 3 is installed in the mounting holes using bolts with reversed threads for detachment. The cutter disc 2, with the cutting blade 3 installed, can extend into the test cylinder 1 and rotate within the soil sample to be tested.

[0060] The drive unit 5 is located at the center of the lower surface of the top plate 44 and is connected to the cutter head 2 via the drive shaft 6.

[0061] Specifically, the drive unit 5 includes a motor and a coupling. One end of the motor is bolted to the top plate 44, and the output shaft of the motor is connected to the coupling. The other end of the coupling is detachably bolted to the upper end of the drive shaft 6, and the lower end of the drive shaft 6 is detachably connected to the central block 21, thus enabling a detachable connection between the drive shaft 6 and the cutter head 2. Therefore, the drive unit 5 drives the drive shaft 6 to rotate the cutter head 2 within the test cylinder 1.

[0062] To provide precise control over the tunneling speed of the cutterhead 2 while it rotates, and to better simulate the erosion of the cutterhead 2 by soil under different geological conditions, the test bench 4 also includes a lifting device 45. The lifting device 45 consists of four electrically operated telescopic struts. The upper ends of the four struts are connected to the edge of the lower surface of the top plate 44, and the lower ends are connected to the edge of the upper surface of the limiting plate 42, providing vertical support between the top plate 44 and the limiting plate 42. The four electrically operated telescopic struts extend and retract synchronously to drive the top plate 44 to reciprocate vertically. The drive device 5 moves synchronously with the top plate 44, thereby driving the drive shaft 6 and the cutterhead 2 to reciprocate vertically. The limiting plate 42 has a first circular hole in its center for the drive shaft 6 to pass through, allowing the drive shaft 6 to move freely through the hole.

[0063] Correspondingly, the shield machine cutter wear prediction device also includes a PLC system control device, which is electrically connected to the drive device 5 and the lifting device 45 to control the drive device 5 to drive the cutter head 2 to rotate inside the test cylinder 1, and to control the lifting device 45 to drive the cutter head 2 to move up and down.

[0064] like Figure 2-5 As shown, in the shield machine cutter wear prediction device of the present invention, the cutterhead 2 is set in a multi-spoke form to simulate the shield machine with spoked panel to the greatest extent.

[0065] Specifically, this invention provides two types of cutter heads 2, with different numbers of spokes 22: a four-spoke cutter head with four spokes 22 and an eight-spoke cutter head with eight spokes 22. The spokes 22 of the four-spoke cutter head are arranged in a cross shape, while the included angle between any two adjacent spokes 22 of the eight-spoke cutter head is 45°.

[0066] Meanwhile, this invention includes three types of cutting blades 3: a shell blade 31, a cutter 32, and a central fishtail blade 33. The shell blade 31 has an arc-shaped cutting edge, is detachably mounted in the first mounting hole, and is arranged on the front end face of the annular cutter holder 23, specifically for cutting sand and gravel. The cutter 32 has a cutting surface inclined to its body, is detachably mounted in the second mounting hole, and is arranged on both sides of the spokes 22. When the cutter head 2 advances forward, it rotates with the cutter head 2, generating axial shear force and radial (tangential direction of the cutter head 2's rotation) cutting force on the excavated soil. At this time, the cutting edge and tip of the cutter 32 insert into the soil, cutting the soil. The central fishtail blade 33 is a fishtail-shaped cutting blade 3, set on the central circular block 21, improving the cutting and mixing effect of the soil in the central part of the cutter head 2. The central fishtail cutter 33 is larger than both the shell cutter 31 and the cutting blade 32, and extends beyond the plane containing the shell cutter 31 and the cutting blade 32 to ensure that the central fishtail cutter 33 cuts the soil first. The central fishtail cutter 33 can be used to first cut the small circular section of soil in the center, and then expand to cut the entire section of soil.

[0067] During simulation tests, the cutting tool block 3 can be selectively mounted on the mounting hole in various arrangements and combinations, which can effectively simulate the wear amount under the collaborative cutting of multiple types of tools in real-world conditions. In this invention, the following four sets of tool assemblies are formed:

[0068] like Figure 2 As shown, the shell cutter 31, the cutting blade 32, and the central fishtail blade 33 are assembled with the four-spoke cutter head to form the first cutter assembly. At this time, multiple shell cutters 31 are arranged on the center line of the spokes 22 of the four-spoke cutter head, multiple sets of cutting blades 32 are arranged on both sides of the spokes 22, and the central fishtail blade 33 is arranged on the central circular block 21.

[0069] like Figure 3As shown, the shell cutter 31 and the central fishtail cutter 33 are assembled with the four-spoke cutter head to form the second cutter assembly. At this time, multiple shell cutters 31 are arranged on the center line of the spokes 22 of the four-spoke cutter head, and the central fishtail cutter 33 is arranged on the central circular block 21.

[0070] like Figure 4 As shown, the shell cutter 31, the cutting blade 32, and the central fishtail blade 33 are assembled with the eight-spoke cutter head to form the third cutter assembly. At this time, multiple shell cutters 31 are arranged on the center line of the spokes 22 of the eight-spoke cutter head, multiple sets of cutting blades 32 are arranged on both sides of the spokes 22, and the central fishtail blade 33 is arranged on the central circular block 21.

[0071] like Figure 5 As shown, the shell cutter 31 and the central fishtail cutter 33 are assembled with the eight-spoke cutter head to form the fourth cutter assembly. At this time, multiple shell cutters 31 are arranged on the center line of the spokes 22 of the eight-spoke cutter head, and the central fishtail cutter 33 is arranged on the central circular block 21.

[0072] The cutter 32 can be in two, four, six or eight groups, and the size of the three types of cutting blocks 3 can be adjusted according to actual needs.

[0073] When the soil consolidation degree in the stratum is higher, the gravel content is higher, and the degree of cementation between sand and gravel is greater, a cutter head 2 with more spokes 22 and a complex arrangement of cutting cutter blocks 3 should be selected.

[0074] In addition, such as Figure 1 As shown, the test cylinder 1 is fitted with a cylinder cover 11 for sealing, ensuring a fully sealed test process. The cylinder cover 11 has a second circular hole at its center that seals with the drive shaft 6. Simultaneously, the cylinder cover 11 has a pressure-increasing hole 111, which allows for pressurization and sealing of the test soil sample during cutterhead 2 excavation, making the test conditions closer to the sealed, pressurized conditions within the cutterhead chamber during actual excavation. The cylinder cover 11 also has a grouting hole 112 for adding soil conditioner.

[0075] The shield machine cutter wear prediction device also includes a data monitoring system. The data monitoring system includes a speed sensor and a torque sensor installed on the drive shaft 6, and a speed sensor installed on the lifting device 45, to investigate the advance distance, time, speed and torque parameters of the cutterhead 2 under different geological conditions. In this way, the combination of the selection of the cutterhead 2 and the layout of the cutting blocks 3 is selected to achieve the highest tunneling efficiency. Combined with the standard of less wear of the cutting blocks 3, the most reasonable selection is proposed to achieve the purpose of predicting the wear of the cutters.

[0076] Based on the above-mentioned shield machine cutter wear prediction device, cutter assembly one, cutter assembly two, cutter assembly three, and cutter assembly four, formed by various cutterheads 2 and various cutting blocks 3, are used to cut test soil samples respectively, and the wear amount of cutting block 3 in each assembly is calculated to realize the shield machine cutter wear prediction method.

[0077] Specifically, it includes the following steps:

[0078] S1: Fill the test soil sample into the test cylinder 1, and cement, consolidate or compact the test soil sample according to the different soil layer conditions to be simulated in the test, so that the height of the test soil sample is less than 70% of the height of the test cylinder 1.

[0079] S2: Weigh the cutting tool block 3 and record its initial mass m1;

[0080] S3: Place the test cylinder 1 containing the test soil sample into the test bench 4, cover it with the cylinder cover 11 through which the drive shaft 6 passes, install the cutter head 2 on the drive shaft 6, start the PLC system control device to control the lifting device 45 to drive the cutter head 2 to descend to the top surface of the test soil sample, and at the same time control the drive device 5 to drive the cutter head 2 to start rotating, so that the cutter head 2 enters the test soil sample while rotating, so that the cutting blade 3 cuts the test soil sample;

[0081] S4: When the cutter head 2 descends to the set depth in the test soil sample, the PLC system control device controls the lifting device 45 to drive the cutter head 2 to the top surface of the test soil sample. At this time, the PLC system control device is turned off, the cylinder cover 11 of the test cylinder 1 is opened, the cutting blade 3 is removed, cleaned, dried and weighed, and the mass m2 of the cutting blade 3 is recorded.

[0082] S5: Change the soil conditions of the test soil sample and the combination of various cutterheads 2 and various cutting blocks 3 according to different test requirements, and repeat S1-S4.

[0083] It should be noted that before each test, the advance distance, i.e. the depth of entry into the test soil sample, is set. Before S3, the rotation speed ω and advance speed v of the cutter head 2 are set by the PLC system control device. During the cutting process of the cutting blade 3 in the soil sample to be tested, the real-time advance distance and corresponding advance time of the cutter head 2 are collected at all times by the data monitoring system.

[0084] The above-mentioned method for predicting the wear of tunnel boring machine cutters can be used to study various soil erosion characteristics, reveal the intrinsic correlation mechanism between the soil and the cutting blade 3, and establish a mathematical expression method for the wear amount δ of the cutting blade 3 rotating and cutting in the test soil sample:

[0085]

[0086] Where R is the diameter of the cutter head 2 (mm);

[0087] N is the rotational speed (rpm) of the cutter head 2;

[0088] v is the feed speed of the cutter head 2 (mm / min);

[0089] L is the helical movement distance (mm) of the cutting tool block 3;

[0090] k is the wear coefficient of cutting tool block 3 (g / mm). 2 ).

[0091] The helical motion distance of the cutting tool block 3 is calculated using the following formula: in,

[0092] X represents the propulsion distance, which is the product of the propulsion time collected by the data monitoring system and the propulsion speed set by the PLC system control device.

[0093] r is the installation radius (mm) of the cutting tool block 3 on the tool disc 2;

[0094] ω is the angular velocity of cutter head 2 (rad / s);

[0095] v is the feed speed of the cutter head 2 (mm / min).

[0096] The wear coefficient k of the cutting tool block 3 is calculated using the following formula:

[0097] in,

[0098] s is the cutting area of ​​the cutting edge of cutting tool block 3 (mm). 2 );

[0099] μ V The abrasive wear constant (dimensionless) of the cutting tool block 3;

[0100] μ ρ To test the adhesive wear constant (dimensionless) of the soil sample;

[0101] Δm represents the mass loss (g) of the cutting tool block 3.

[0102] The mass loss factor Δm of cutting tool block 3 is calculated using the following formula: Δm - m1 - m2; where...

[0103] m1 is the initial mass (g) of the cutting tool block 3;

[0104] m2 is the mass (g) of the cutting tool block 3 after wear.

[0105] The diameter R of the cutter head 2, the installation radius R of the cutting blade 3 on the cutter head 2, and the cutting area S of the cutting blade 3 were all obtained by measurement. The adhesive wear coefficient μ of the test soil sample was also measured. p The abrasive wear coefficient μ of the cutting tool block 3 can be obtained by referring to "Archard's Wear Design Calculation Model and Its Application Method" from the Institute of Tribology, Hefei University of Technology. V It can be obtained from "Principles of Tribology" published by Tsinghua University.

[0106] Further analysis can be conducted by using three-dimensional laser point cloud reverse modeling to analyze the wear condition of each cutting tool block 3 after the experiment, in order to discover the wear type, wear area and wear characteristics under the synergistic effect of multiple types of tools. The analysis can be combined with the calculation of the wear amount δ formula and the point cloud reverse modeling to obtain a unified quantitative characterization method for the damage type of cutting tool block 3 under the synergistic effect of single-type cutting tool block 3, multiple-type cutting tool block 3 and new-old cutting tool block 3.

[0107] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0108] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for predicting cutter wear in tunnel boring machines, characterized in that, A shield machine cutter wear prediction device is used, which includes multiple cutterheads (2) and multiple cutting blocks (3). Multiple cutterheads (2) and multiple cutting blocks (3) are selected in sequence and combined to cut test soil samples. The wear amount of the cutting blocks (3) in the test soil sample is obtained by the following formula. (g / mm): ; in, The diameter (mm) of the cutter head (2) is given. The rotational speed (rpm) of the cutter head (2) is given. The feed speed of the cutter head (2) is (mm / min); The spiral motion distance (mm) of the cutting tool block (3) is given. The wear coefficient (g / mm) of the cutting tool block (3) 2 ); The helical motion distance (mm) of the cutting tool block (3) is calculated using the following formula: ； in, The distance traveled (mm); The installation radius (mm) of the cutting tool block (3) on the cutter head (2); ω is the angular velocity (rad / s) of the cutter head (2); The feed speed of the cutter head (2) is (mm / min); The wear coefficient of the cutting tool block (3) is calculated using the following formula. : ; in, The cutting area (mm) of the cutting edge of the cutting tool block (3) 2 ); The abrasive wear constant (dimensionless) of the cutting tool block (3); The adhesive wear constant (dimensionless) of the tested soil sample. The mass loss (g) of the cutting tool block (3); The cutter head (2) includes a central circular block (21), spokes (22) and an annular cutter holder (23). The central circular block (21) is located at the center of the annular cutter holder (23). The central circular block (21) and the annular cutter holder (23) are connected by the spokes (22). The spokes (22) extend along the radius of the annular cutter holder (23) and are evenly arranged in a circle within the annular cutter holder (23). The spokes (22) are provided with multiple mounting holes. The cutting blade (3) is detachably mounted in the mounting holes by bolts. It includes two types of cutter heads (2), namely a four-spoke cutter head including four spokes (22) and an eight-spoke cutter head including eight spokes (22); On the bottom surface of the spoke (22), a plurality of first mounting holes are arranged equidistantly along its length direction, and the first mounting holes are located on the center line of the spoke (22); On both sides of the spoke (22), a plurality of second mounting holes are arranged at equal intervals along its length direction, and the second mounting holes are symmetrical about the center line of the spoke (22). It includes two types of cutting blades (3), namely a shell cutter (31) and a cutter (32), wherein the shell cutter (31) can be detachably installed in the first mounting hole, and the cutter (32) can be detachably installed in the second mounting hole.

2. The method for predicting cutter wear of a tunnel boring machine according to claim 1, characterized in that, The mass loss of the cutting tool block (3) is calculated using the following formula. : ; in, The initial mass (g) of the cutting tool block (3) is given. The mass (g) of the cutting tool block (3) after wear.

3. The method for predicting cutter wear of a tunnel boring machine according to claim 1, characterized in that, Includes the following steps: S1: Put the test soil sample into the test cylinder (1), and cement, consolidate or compact the test soil sample according to the different soil layer conditions to be simulated in the test; S2: Weigh the cutting tool block (3) and record its initial mass. ; S3: The cutter head (2) descends to the top surface of the test soil sample, and the cutter head (2) begins to rotate, so that the cutter head (2) enters the test soil sample while rotating, and the cutting blade (3) cuts the test soil sample; S4: After the cutter head (2) descends to the limit position inside the test soil sample, the cutter head (2) rises to the top surface of the test soil sample, the cutting blade (3) is removed, cleaned, dried, and weighed, and the mass of the cutting blade (3) is recorded. ; S5: Change the soil conditions of the test soil sample and the combination of the various cutter heads (2) and the various cutting blocks (3) according to different test requirements, and repeat S1-S4.

4. The method for predicting cutter wear of a tunnel boring machine according to claim 3, characterized in that, The shield machine cutter wear prediction device also includes a test bench (4), which includes a vertical support rod (41), a limiting plate (42) and a base (43). The limiting plate (42) is located parallel above the base (43). The vertical support rod (41) is vertically supported between the limiting plate (42) and the base (43). The upper end of the vertical support rod (41) is connected to the edge of the lower surface of the limiting plate (42), and the lower end of the vertical support rod (41) is connected to the edge of the upper surface of the base (43). The test cylinder (1) is placed on the base (43) and located between the limiting plate (42) and the base (43).

5. The method for predicting cutter wear of a tunnel boring machine according to claim 4, characterized in that, The test bench (4) also includes a top plate (44) and a lifting device (45). The top plate (44) is located parallel above the limiting plate (42). The lifting device (45) is vertically supported between the top plate (44) and the limiting plate (42). The upper end of the lifting device (45) is connected to the edge of the lower surface of the top plate (44), and the lower end of the lifting device (45) is connected to the edge of the upper surface of the limiting plate (42). The lifting device (45) consists of four electric telescopic struts. The four electric telescopic struts extend and retract synchronously to drive the top plate (44) to reciprocate in the vertical direction.

6. The method for predicting cutter wear of a tunnel boring machine according to claim 5, characterized in that, The shield machine cutter wear prediction device also includes a drive device (5), which is located at the center of the lower surface of the top plate (44). The drive device (5) moves synchronously with the top plate (44) in the vertical direction. The drive device (5) is connected to the cutter head (2) through a transmission shaft (6). The upper end of the drive shaft (6) is detachably connected to the drive device (5), and the lower end of the drive shaft (6) is detachably connected to the central block (21). The driving device (5) drives the transmission shaft (6) to reciprocate in the vertical direction to drive the cutter head (2) to move synchronously. The driving device (5) drives the transmission shaft (6) to drive the cutter head (2) to rotate inside the test cylinder (1).

7. The method for predicting cutter wear of a tunnel boring machine according to claim 6, characterized in that, The shield machine cutter wear prediction device also includes a PLC system control device, which is electrically connected to the drive device (5) and the lifting device (45) to control the start and stop of the drive device (5) and the lifting device (45). Before S3, the rotational speed of the cutter head (2) needs to be set via the PLC system control device. With propulsion speed Furthermore, during the cutting process of the cutting blade (3) in the soil sample to be tested, the real-time advance distance and corresponding advance time of the cutter head (2) are collected at all times.

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